Forgotten Antibiotics

18 Jan 2012
Authors:
Hellen Gelband

It was a why didn t I think of that? moment: an article called Forgotten Antibiotics: An Inventory in Europe, the United States, Canada, and Australia, in the January 15 issue of Clinical Infectious Diseases (CID).   A group of experts surveyed all systemic antibiotics that have been approved in the United States, Europe, Canada, and Australia and identified those no longer in common use.  Reviewing available data, they assessed the value (known or potential) of these antimicrobial agents against the most common hard-to-treat resistant infections, using criteria they specified.  What a great idea!  It doesn t replace a search for new antibiotics, but it adds to the picture.

The researchers settled on 33 antibiotics that seemed to be of value and then surveyed the 38 countries to find out which antibiotics were available where.  More than half the drugs were available in fewer than half the countries and only a few were available in most.

The authors discuss several agendas that emerge from this work for the study s high-income countries, but I am most interested in what this means for lower income countries.  And it relates to a survey that the principal investigator of our Global Antibiotic Resistance Partnership project in Vietnam (GARP-VN), Heiman Wertheim, fielded just last summer on colistin, one of the forgotten antibiotics.   In Vietnam the use of colistin was increasing, used for some of the most resistant Gram-negative hospital-acquired infections.  But colistin was not available officially in the country.  At the direction of their doctors, patients (or people acting for patients) buy colistin of unknown quality at pharmacies and bring it to the hospital to be administered intravenously.  Because it is an old drug, first used in patients in the 1950s, the kinds of studies we take for granted to optimize dose and regimen have not been done.   And anyway, the resistant organisms that colistin is now pitted against didn t exist then.

To find out about how colistin was being used in other countries, Dr. Wertheim sent out an internet questionnaire to professionals all over the world.  About 300 people responded from 56 countries on every continent where there are countries.  As suspected, it was used in different doses, regimens and with different partners.  Worryingly, as Dr. Wertheim had observed himself, it was clearly underdosed in many patients, risking loss of effectiveness to resistance.  Even though colistin is an old drug, it can be expensive (at least in Vietnam) and people tend to buy as little as possible.  The irony is that colistin is used widely in pigs and chickens so it must be available cheaply in the agricultural sector.  A final report of the colistin survey is not yet published, but it should lead to research to learn how to use it and how to protect it.

The CID study adds weight to the importance of reviving these older drugs that have gone out of use most because they don t bring in much money for the manufacturers.  But the fact is that at least a few entries on the list are not forgotten in developing countries.  In fact, they have never left the first-line arsenal of lower income countries because the new drugs are out of financial reach of most ordinary people.  With our local partners, we are going to find out more about the 33 drugs in the countries that are part of GARP.   Maybe some are already being used in ways we don t fully understand.  Or, maybe some real winners will emerge that are effective and affordable where the ones being used are neither.  And we will be knowledgeable enough voice the needs of professionals and the public in low- and middle-income countries, which as we have observed through GARP for other antibiotic-related issues may be different from the needs in high-income countries.   


Image credit: Flickr: sappymoosetree